Oregon was underwater in their rushing attack, and everything else that happened in this game proceeds from that fact. Outside of garbage time, they rushed on a 2:3 basis compared to passing, far less frequently than the rest of the year, and had just 6 successful designed rushes vs 8 unsuccessful ones, given the down & distance. They ran for only 3.8 yards per carry on those rushes and only two went for 10+ yards.
A few of those failed rushing plays were one-offs — a holding flag, a reverse play the defense wasn’t fooled by, a well-blocked chunk run but on 3rd & 19 — but the rest were simply losing blocks and getting overwhelmed by a defense that was determined to take away the run.